Concrete in Australia Vol 36 No 4 33
away from coasts. e environmental exposure in those areas is
generally classified as A1 and A2, while the exposure of near-coastal
and coastal areas is classified as B1, B2 or C (or C1/C2) where a
higher cover thickness is required. Meanwhile, a greater increase
in the probability of corrosion initiation due to climate change is
also found in the areas with a spatial pattern similar to the changes
of carbonation depth.
In the absence of climate change, carbonation induced corrosion
damage is in the range of 0 and 25%, depending on region (Figures
5(e) and (f )). Under climate change, its probability varies regionally
from a 19% decrease to a 15% increase in corrosion damage risk,
with a spatial pattern similar to that for corrosion initiation.
Unlike carbonation induced corrosion, chloride penetration
induced corrosion mostly occurs around coastal regions and inland
areas where salinity and water exposure are high. As shown in
Figure 6, the probability of chloride induced corrosion initiation
varies widely by region, from 0 in southern Australia to 34% in
the north. Chloride induced corrosion initiation is much less
Figure 5. Carbonation induced corrosion of concrete structures by 2100: (a) mean carbonation depth without consideration of climate change,
(b) change in carbonation depth for A1Fl emission scenario, (c) probability of corrosion initiation without consideration of climate
change, (d) change in probability of corrosion initiation for A1Fl emission scenario, (e) probability of corrosion damage without
consideration of climate change, (f) change in probability of corrosion damage for A1FI.
(a)
(c)
(d)
(b)